1. Technical Field
The Present invention relates to digital video editing systems and methods. The systems and methods of the invention are particularly well suited for editing and preparing sports training videos, football “game films” in particular.
2. Related Art
One area of athletics where video plays a very important role is the production of “game films.” Today sporting events are typically recorded using digital video recorders. However, in keeping with standard usage, the present disclosure refers to video recordings of sporting events as “game films” even though there may be no film involved. Game films play an especially large role in preparing football teams to meet upcoming rivals. At almost all levels, little league, high school, college and professional, football teams routinely review films of their own previous performances too learn what they can improve on in their upcoming games. Teams also review films of their opponents in order to become acquainted with the other team's play calling tendencies, pass routes, defensive formations, and overall strengths and weaknesses.
The advent of digital video recorders has altered the concept of “game films” considerably. In the past, game films were literally movie films which were played essentially from beginning to end, perhaps with the ability to stop and reverse the tape and to selectively play portions of the film in slow motion. Editing such films required actually cutting the films and stitching them together at desired locations. This arduous process had the common effect of significantly limiting the amount of editing most coaching staffs were willing or able to do to produce more efficient training films. With digital video, however, editing video images from previous games is much simpler, and “game films” have become much more sophisticated.
Today game films typically include video from multiple sources capturing the action from multiple angles. For example teams will commonly use up to four video cameras to capture: 1) a wide angle view of the game from the press box, 2) a tight angle view, again from the press box perspective, 3) an end zone view; and 4) a reverse angle view from the opposite side of the field, a sideline view, or a view from some other angle. Each play may be recorded as an individual video file. After the game, or after receiving the video files from an opposing team's previous games, a coach or member of the coaching staff may assemble the various video files recorded during the course of a game as he sees fit, creating a customized video presentation of specific plays that the coach finds especially instructive. Furthermore, the coach may select different plays and different camera angles to create separate training videos for different position players. For example, a quarterback training video may concentrate on defensive pass plays from an opponent's previous games in order for the quarterback to become familiar with the opposing team's defensive formations and pass coverage schemes. Line coaches may prepare videos that include tight angle shots to more clearly show blocking techniques and assignments. Training videos may even include several versions of the same key plays recorded from multiple angles to glean as much information as possible from the opponent's past performances. The coach may even opt to include plays from a number of different games in the same video presentation. Coaches may also want to view plays that reflect key points in a game or series of downs. For example, coaches may want to view all third down plays, or only short yardage plays, and the like.
When multiple video capture devices are employed it becomes difficult to synchronize and align the video files from each source. As mentioned above, each play is typically recorded as a separate video file. When multiple cameras are used to record a game, each camera records the same events, but each from a different perspective. Because of their different perspectives, the video recorded by different cameras may appear significantly different when reviewed for editing purposes. Ideally, each camera recording a game will record a equal number of plays and the video files generated by each camera may be aligned or matches sequentially so that the first video file from each of the cameras will correspond to the first play of the game, the second video file from each camera will correspond to the second play, and so forth. In practice, however, this is rarely the case. Different camera operators may start and stop their cameras at different times. Occasionally a camera operator may forget to stop the camera at the end of a play so that a particular video file may include two consecutive plays rather than just one. Similarly, a camera operator may forget to turn on the camera so that one or more plays may be absent from video stream generated by one of the video sources.
In preparing sophisticated video game films it is important that the person assembling the films knows that he or she is looking at the same event from each of the different video sources when reviewing the captured video. Because the video from the different camera angles may appear significantly different for the same event, manually aligning the video files from each camera can be a difficult and time consuming task.
Another factor in the preparation and viewing of video game films is time. Coaches typically have limited time to spend with their players. Often it is more valuable for coaches to spend time drilling their players on the practice field rather than lecturing them in front of game films. Today's video technology allows coaches to prepare films that may be stored on portable media so that the players can review the films on their own time out of the presence of the coaching staff. Coaches may want to add commentary to such portable game films, and may wish to control the manner the individual video clips are played back. For example a coach may want to repeat a particular play several times, or replay the same play from several different angles, or play certain plays in slow motion, and the like. Heretofore coaches have not had the ability to synchronize a voice over layer with a sophisticated video stream including the types of playback features described above.
Finally, although sending game films home with the athletes on DVDs may be a more efficient way to get game films in front of players' eyes and for coaches to communicate important information to their players, some coaches nonetheless cannot pass up the opportunity to lecture players in person as they watch game films. Like the coaches preparing prerecorded training videos, live, stand-up coaches may also want to control the order and manner in which video files are played back. For example, as the coach is speaking the coach may want to have the ability to repeat a play several times, or replay the same play from several different angles, or play certain plays in slow motion, and the like. In order to accomplish this, the various video files must be accessed and played back in real time. The video files may be stored on a DVD or in a digital video database or some other medium. A computer may be used to access the video data and send the video to a display device such as a projector. An interface is needed to allow a coach or other user to quickly and easily access and control the playback of video files “on-the-fly” in order to control the display of video files in a live setting.